/* 表单容器 */
form {
    max-width: 600px;
    margin: 20px auto;
    padding: 20px;
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

/* 表单标题 */
h3 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
    font-size: 24px;
}

/* 表单标签 */
form label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: #333;
}

/* 表单输入框和选择框 */
form input, form select, form textarea {
    width: 100%;
    padding: 10px;
    margin-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
    box-sizing: border-box;
}

/* 文本框 */
form textarea {
    resize: vertical;
    min-height: 100px;
}

/* 提交按钮 */
form button {
    display: block;
    width: 100%;
    padding: 10px;
    font-size: 16px;
    font-weight: bold;
    color: white;
    background-color: #4A90E2;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

form button:hover {
    background-color: #357ABD;
}

#cancel-btn {
    background-color: #f44336;
    color: white;
    border: none;
    padding: 10px;
    cursor: pointer;
    border-radius: 4px;
    margin-top: 20px;
    transition: background-color 0.3s ease;
}

#cancel-btn:hover {
    background-color: #ff0000;
}

@media (max-width: 768px) {
    form {
        padding: 15px;
    }

    form button {
        font-size: 14px;
    }
}

.course-image {
    max-width: 100%;
    max-height: 300px;
    display: block;
    margin: 10px auto;
    object-fit: contain;
}

.checkbox-group label {
    margin: 0;
    padding: 0;
    display: inline-flex;
    align-items: center;
    vertical-align: top;
    line-height: 1.5;
    margin-right: 15px;
}

.checkbox-group input[type="checkbox"] {
    margin: 0 8px 0 0;
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}